I know the alternator has to be added but my question is can the ecm be reflashed to do away with the hybrid stuff? Anyone familiar with this powertrain? Is there other stuff to take into consideration? From the info I found, it seems to be an LM7.

hybrid? do you mean flex fuel? if so yes you can tune it out and it will run just fine. what year is your engine?

No. An actual Hybrid with an electrical machine in place of the torque converter. There is no alternator or starter on this engine. I was thinking of locating a harness off a regular 5.3 and adding the missing components. I guess i was curious if the tranny could be used and what possible issues the pcm could give me. I am sure a reflash would solve the hybrid stuff but there isn't much info out there on this setup.

I'm pretty sure the electric motor is in addition to a torque converter.